Hey so I got new clear taillights for my 99 civic coupe and I installed them with brand new LED bulbs, and when I tested them out, the signals and hazards would not turn on without pressing on the breaks. It would all work fine while I pressed on the breaks. Without the breaks though, the signal lights would turn on but it’s not bright at all, and I could barely see it. Anyone know the issue and how to fix it?

 

It sounds like the wiring may be off, was this a direct plug in or did you have to cut wires?

The constant wire seems like it may be wired to the wire that is sending the brake signal.

 

i didnt touch any wires, it was all plug and play basically. I just plugged in the new bulbs and then connected the original wires in the car to the taillights wire. Also should mention that I had only one of the new taillights installed at one point and it was working fine. The issue started when I finally got both installed

 

I think the LED taillights are the problem. Did you install a relay? Did you try the new taillights with the old bulbs?

 

i did not install a relay, but i will definitely try to use the old bulbs to see what the issue is, im gonna come back to this thread tho when i do that and let u know

 

You shouldn't need to install any extra relays or load resistors. You will need to change your flasher relay out for an LED flasher to eliminate the 'hyperflash'. It's $13 at Autozone:

https://www.autozone.com/electrical-...p34/849389_0_0

Sounds to me like you are missing a ground somewhere, so you are backfeeding through the brake light circuit somehow.

Sounds dumb, but are the bulbs installed 'backwards'? LEDs are directional and won't work if the polarity is reversed (that's the diode part).

 

Thanks I really appreciate the help.
I checked the bulbs if they were in backwards and fixed it, but still has the same issue? How do I check for a missing ground?

 

check your grounds. bad grounds can cause all kinds of weird problems. also you may have to put load resistors on those LED's.

 

I kind of found the issue but I don’t know how to fix it, so I put the oem bulbs in just the right trunk taillight and everything works fine. Hazards, signals work the way it’s suppose to, but when I replace the oem with the matching LED bulbs the other taillights have, I still have the same issue. I’ve even took the wiring from the oem taillights I have and put it in my new ones so I don’t know if it’s still a wiring issue or not